International Business Machines Corporation

John M Mullen

Challis Llewellyn Purrington

Laura Ann Weaver

Andrew Keith Boggs

Joe Jacobs

Quy N Hoang

Hayden C Cranford, Jr

Vernon Roberts Norman

Joseph Kinman Lee

Charles R Hoffman

Stacy J Garvin

Joel Erwin Geyer

Kenneth T Wilson

Kathleen Miriam Wilhelm

Wendy K Hodgin

An intelligent multistation access unit is provided having a transmission speed detection circuit for determining the data transmission speed of an attached device attempting to gain access to a node of a multiple transmission rate digital data communications network. The intelligent multistation access unit is comprised of a speed detect circuit, which indicates the data transmission speed of the attached device, a switching circuit which directs the attached device to the speed detect circuit until switched to allow the attached device access to the network node, and a processor that controls the switching circuit and which permits the attached device access to the node depending on the data transmission speed indication.

Intelligent concentrator for multiple speed data communications systems

Dual detection paths containing speed recognition devices automatically determine the rate at which data is being transmitted on a multi-rate digital data communications network such as a token ring network. The multiple detection paths operate simultaneously with each detection path provided with a Phase Lock Loop (PLL) and a pattern recognition device. The PLL and its associated pattern recognition device are made to operate at one of the known ring speeds. The ring speed is determined by the detection path which is able to recognize a predetermined data pattern from the network.

Token ring speed detector

The internal electrical noise generated by circuits of a VLSI chip is controlled by separating the logic circuit substrate contacts from the logic circuits ground contacts. A separate return path interconnects each contact to card ground. Further noise reduction is achieved by providing a void region between the noise generating devices and the 'quiet' devices. A substrate contact ring is provided in the void region. The substrate contact ring is connected by a separate path to card ground.

Substrate noise coupling reduction for VLSI applications with mixed

A level selectable FET voltage generation system is described. The system includes a single charge pump controlled by multiple feedback paths and a powerdown circuit. Each feedback path contains a capacitor divider network, a sense amplifier with a compensating voltage reference and a timer which periodically resets the capacitor divider network to insure sensing accuracy. The powerdown circuit and a selected feedback path provides a desired voltage level at the output of the charge pump.

On chip multiple voltage generation using a charge pump and plural

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Wake Forest, NC, United States of America

John M Mullen